Hydraulically-powered impact tools are well-known. A charge of energy is abruptly released to drive a hammer that strikes a tool. An excellent example of such a tool is shown in Ottestad's U.S. Pat. No. 4,111,269, issued Sept. 5, 1978, which is incorporated in its entirety by reference, as though fully set forth herein. It is especially incorporated for its showing of a means to drive a hammer (gas chamber 17, loading chamber 25, piston 35 and piston head 55 therein), and the hammer itself (piston head 55 and piston rod 56, therein called "driving member"). The hammer therein drives a tool 86.
The conventional means for mounting a tool is to place it inside a long bearing, limiting its upward movement by some kind of stop shoulder. The hammer impacts the tool to drive it into the work. In order to withstand bending loads that might be applied as the tool is driven into the work, the length of the tool in the bearing is usually two or three times the diameter of the tool. Thus if a four inch diameter tool is used, the bearing must be 8 to 12 inches long. This is disadvantageous, especially when the tool must be used in close quarters.
It is an object of this invention to provide tool mounting means which can be made more compact and shorter, which can resist substantial bending loads, which can seal the assembly against chips and dust, which can penetrate the work, and which can be retained by non-mechanical means.